666266624 has 44 divisors (see below), whose sum is σ = 1345026384. Its totient is φ = 329846784.

The previous prime is 666266609. The next prime is 666266651. The reversal of 666266624 is 426662666.

It is a super-2 number, since 2×666266624² = 887822428512714752, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102314 + ... + 108630.

Almost surely, 2^666266624 is an apocalyptic number.

666266624 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666266624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (672513192).

666266624 is an abundant number, since it is smaller than the sum of its proper divisors (678759760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666266624 is a wasteful number, since it uses less digits than its factorization.

666266624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6440 (or 6422 counting only the distinct ones).

The product of its digits is 746496, while the sum is 44.

The square root of 666266624 is about 25812.1410192956. The cubic root of 666266624 is about 873.4056950446.

The spelling of 666266624 in words is "six hundred sixty-six million, two hundred sixty-six thousand, six hundred twenty-four".